PMMA Composites Research Articles

Tunable luminescence and transmittance nature of CdS:PMMA nanocomposites for optoelectronic applications

Optical and energy storage materials based on semiconductors are of great interest today. The present report explains the semiconductor nanocomposite centered on highly transparent Poly(methyl methacrylate) (PMMA) matrix and Cadmium Sulphide (CdS) nano particles. The solid films of CdS:PMMA composite was prepared using simple and cost effective solution casting technique. The surface morphology and the presence of CdS particles in PMMA matrix was analysed using Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectra (EDX). The size of the particles was analysed using Atomic Force Microscopy (AFM) and Transmission Electron Microscope (TEM) and they revealed the presence of nano sized particles. The narrow size distribution of particles was identified from TEM and AFM analysis. The transmittance of the CdS:PMMA nanocomposite solid films was found to be above 90%. The blue and green emission of CdS:PMMA nanocomposite solid films were observed from Photoluminescence (PL) spectra.

Mechanical characterization of polymethyl methacrylate composites reinforced with surface‐coated carbon fibers

Using trihydroxy polyether polyol (PPG), diphenylmethane diisocyanate (MDI) as soft segment and hard segment, carbon fiber (CF) as reinforcement, and self‐crosslinking CF/polymethyl methacrylate (PMMA) composite was prepared by prepolymer method. In this study, starch and octanoyl chloride were esterified to obtain esterified starch (SE). The fiber is then melt blended with PMMA matrix to prepare PMMA composite. Fourier‐transform infrared spectroscopy (FTIR) and SEM were used to analyze and characterize the composites produced. The results show that the composite material was prepared by separately modifying the fiber with NaOH and SE, respectively. The mechanical properties of the composite materials prepared by the modified fiber are improved, and the fiber and the PMMA matrix showed better compatibility. The mechanism of comodified fiber enhanced the mechanical properties of its composites.

Effect of surface treatment on surface characteristics of carbon fibers and interfacial bonding of PMMA resin composites

ABSTRACTCarbon fiber (CF) as reinforcement, self-crosslinking carbon fiber/PMMA prepared by prepolymer method (CF/PMMA) composite. The fiber is then melt blended with PMMA matrix to prepare PMMA composite. Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were used to analyze and characterize the composites produced. The results show that the composite material prepared by separately modifying the fiber with plasma, aqueous ammonia and HNO3 solution. The mechanical properties of the composite materials prepared by the modified fiber are improved, and the fiber and the PMMA matrix shows better compatibility.

Synergistic effect of carbon nanotube and graphene nanoplates on the mechanical, electrical and electromagnetic interference shielding properties of polymer composites and polymer composite foams

Novel PMMA composites were fabricated using two different dimensional nanofillers of MWCNTs and GNPs as bifillers to explore their synergistic effect on the final mechanical and electrical properties. MWCNTs and GNPs display limited effect on the final electrical properties while they show obvious synergistic effect in influencing the mechanical performance. The well-dispersed MWCNTs-GNPs in polymer matrix provide plenty of 1D-2D interconnections for efficient stress transferring when exposed to stress tensile, but the critical distance between nanofiller is not enough for effective electron movements and the significant Schottky barrier between nanofiller contacts has restricted the synergistic effect for electrical properties. Afterwards, PMMA composite foams with microcellular structure were prepared by supercritical fluid assisted processing. The ternary bimodal composite foams present better tensile, electrical and EMI shielding properties than the unimodal composite foams. MWCNTs and GNPs reveal prominent synergistic effect in influencing the tensile and electrical properties of ternary composite foam systems. The obvious enhancement of electrical conductivity results from the in situ exfoliation of GNPs, high-level orientation and redistribution of nanofillers, moderate physical foaming with bimodal microcellular structure as well as attenuated Schottky barriers at few-layer graphene/MWCNTs junctions. The dramatic improvement of EMI shielding performance is attributed to the elevated electrical conductivity, unique foam microstructures and special 1D-2D (MWCNTs-GNPs) hybrid structure. This study paves a feasible road to prepare lightweight and novel composites with superior electrical properties.

Luminescent Nanofluids of Organometal Halide Perovskite Nanocrystals in Silicone Oils with Ultrastability.

Luminescent nanofluids are successfully prepared by directly dispersing organometal halide perovskite nanocrystals (OHP NCs) with different emission colors in silicone oils. The photoluminescence quantum yields of nanofluids with green, blue and red emission are 47, 32, and 19%, respectively. Furthermore, the nanofluids greatly enhance the stability of OHP NCs and show excellent resistance against moisture, heat and ultraviolet light. The luminescent nanofluids can be used as liquid color converter for LED. By loading them onto silica aerogel, luminescent perovskite powders were achieved. Their applications as phosphor additives for preparing luminescent PMMA composites were demonstrated.

Effect of nitrile butadiene rubber/Al2O3/YSZ fillers for PMMA denture base on the thermal and mechanical properties

This study is to investigate the effect of nitrile butadiene rubber (NBR as impact modifier) together with Al2O3/YSZ (toughening) as filler loading in PMMA denture base on the thermal and mechanical properties. PMMA matrix without fillers was mixed between PMMA powder and 0.5 mass% of BPO, and it is used as the control group. The liquid components consist of 90% of methyl methacrylate (MMA) and 10% as the cross-linking agent of ethylene glycol dimethacrylate. The denture base composites were fabricated by incorporating PMMA powder and BPO and fixed at 7.5 mass% NBR particles and filler loading (1, 3, 5, 7 and 10 mass%) of Al2O3/YSZ mixture filler by (1:1 ratio) as the powder components. The ceramic fillers were treated with silane (γ-MPS) and the powder/liquid ratio (P/L) according to dental laboratory practice. The TGA data obtained show that the PMMA composites have better thermal stability compared to unreinforced PMMA, while DSC curves show slightly similar Tg values. DSC results also indicated the presence of unreacted monomer content for both reinforced and unreinforced PMMA composites. The fracture toughness, Vickers hardness and flexural modulus values were statistically increased compared to the unreinforced PMMA matrix (P < 0.05).

Study the Effect of Nano-Al2O3 and Fiber Glass on Mechanical and Physical Properties of PMMA Composites for Prosthetic Denture

Study the Effect of Nano-Al2O3 and Fiber Glass on Mechanical and Physical Properties of PMMA Composites for Prosthetic Denture

Post-process composition and biological responses of laser sintered PMMA and β-TCP composites

Abstract

Mechanical properties of diamond nanothread reinforced polymer composites

One-dimensional diamond nanothread (DNT) has drawn intensive research interests and become a promising candidate for nanocomposites reinforcement. This paper explores the mechanical properties of DNT reinforced poly (methyl methacrylate) (PMMA) composite under tensile deformation via molecular dynamics simulation. The study shows that the Young's modulus and yielding stress of PMMA composite are enhanced by 85% and 15% with the incorporation of DNT. Remarkably, DNT which is a hydrogenated carbon nanotube (CNT) is proved to strengthen PMMA composite more effectively than CNT for a similar structure. The outstanding strengthening of DNT is attributed to interfacial interaction and mechanical interlocking between DNT and PMMA matrix. A pull-out simulation is conducted to examine the interfacial shear strength of DNT-PMMA interface and comparison studies are made with that of CNT-PMMA interface. The results reveal that DNT has higher load transference within PMMA composite than CNT, by presenting 34% above CNT in interfacial shear strength. It is also demonstrated that DNT morphology can significantly affect the interfacial interaction and mechanical interlocking with PMMA matrix, leading to distinguished reinforcement efficiency for PMMA composite. These findings will shed light to DNT application in nanocomposites and provide an important insight into reinforcing mechanism.

Multifunctional nano‐ZnO/PMMA composites with high transparency prepared by one‐step in situ polymerization

Multifunctional nano‐ZnO/PMMA composites have wide application prospects in many fields such as antibacterial, photocatalysis, photoluminescence, and UV resistance. For mass production, one‐step in situ polymerization process was employed to prepare nano‐ZnO/PMMA composites, which is simple, environmentally friendly, and economical. The growth of nano‐ZnO was inhibited by PMMA thus nano‐ZnO with small particle sizes of 3–5 nm was dispersed homogeneously in PMMA matrix. Thermal stability and molecular weight of nano‐ZnO/PMMA composites were enhanced obviously in comparison with pure PMMA. Nano‐ZnO/PMMA composites with high visible transparency (91.8% at 600 nm) and efficient UV‐shielding capacity (97.7% at 320 nm) can be used as a substitute for inorganic glass and further extended to optical sensors or optical filters. In addition, the blue‐green luminescence emission under UV light makes nano‐ZnO/PMMA composites a promising candidate for promoting the photosynthesis of plants. POLYM. COMPOS., 40:657–663, 2019. © 2018 Society of Plastics Engineers

Electromagnetic and microwave absorption characteristics of PMMA composites filled with a nanoporous resorcinol formaldehyde based carbon aerogel.

Nanostructured carbons have opened up new perspectives in fields of electromagnetic (EM) applications. The present study aims at the processing of microwave absorbing (MA) materials based on carbon aerogels (CAs) in polymethyl methacrylate (PMMA) matrix to be used in X-band frequency. CAs were synthesized by carbonization of a sol–gel derived organic gel from resorcinol and formaldehyde as starting materials. Microwave attenuation properties of the prepared composites were investigated in terms of CAs particle size distribution (PSD) and mass fraction. To do so, the optimal PSD was initially determined by assessing the EM attenuation performance of the CAs/PMMA composites with constant mass loading (10 wt%) and differing particle sizes. Next, the EM properties of the selected CAs with the optimal particle size was measured as a function of mass fraction varying from 1 to 15 wt% in order to obtain a highly efficient CAs based MA. The results indicate that the dielectric loss of CAs composites can be enhanced by optimizing the PSD as well as the mass fraction of CAs. The effective absorption bandwidth of composites containing 10 wt% of CAs exceeded 3.7 GHz at a very thin thickness of 1.9 mm indicating that these materials present advantages as microwave absorbers.

The investigation of the friction and wear properties of surface‐treated carbon fiber/SiO2 reinforced PMMA composites

The mechanical properties of SiO2 filler particles on carbon fibers have been under discussion for several decades; the diverse models, and the properties of the components relevant to retention, are critically reviewed in the first part of this study. In addition, to gain an insight into some possible combined effect of the carbon fiber/poly(methyl methacrylate) (CF/PMMA), interfacial adhesion strength and the tensile properties and dielectric strength of the hybrid composites were studied. Simple modified rules of mixtures are used to estimate the fiber efficiency factors for the strength and modulus of the hybrid composites. Except, with the increasing fraction of CFs in PMMA, the weld line area's elongation percent is decreased. Whereas for case of SiO2, the 10 wt% is the threshold for micro injection molded weld line tensile strength and dielectric strength turning from decrease trend to increase. Same as CF, elongation of micro weld line samples is in general lower than neat PMMA as well, due to the addition of SiO2 particles.

An investigation on the effect of surface treatment of bamboo fiber-filled PMMA composite

Polymeric composites have steadily gained importance in recent years for industrial applications. The increase in use calls for a better understanding of their behavior under different working environments. Friction and wear are considered two important parameters that govern tribological behavior. In this study, the friction and wear characteristics of bamboo fiber-Polymethyl methacrylate (PMMA) and MoS2 filler in PMMA composites were experimentally investigated at varied loads and sliding velocities. From this investigation, it was found that the addition of MoS2 in PMMA composite system showed least coefficient of friction and highest wear resistance.

The investigation on the effect of surface radiation oxidation of bamboo fiber‐filled PMMA composite

The aim of this investigation was to study the effect of surface thermal oxidation of bamboo/poly(methyl methacrylate) composite by irradiation. Thermal oxidative effects on the surface energy of bamboo fiber were measured by radiation as a function of exposure time and temperature. Oxidized bamboo/poly(methyl methacrylate), after exposure to air at temperatures of 100°C and 110°C, had a range of maximum surface energies from 38 to 41 mJ/m2. Comparisons between Fourier transform infrared carbonyl peak growth and the surface energy showed that both methods detect oxidation, though the increase in surface energy was detected before the carbonyl peak growth was noticeable. The work of adhesion predicted by the surface free energies obtained in this work between a coated calcium carbonate and bamboo fiber changes by 10% due to the oxidation of the polymer at 110°C. The structural results were discussed in the oxidation chemistry of the macromolecule.

Near-infrared luminescence of Bi2ZnOB2O6:Nd3+/PMMA composite

Near-infrared luminescence of a novel polymer composite system: PMMA doped with Bi2ZnOB2O6:Nd3+ microparticles, is reported for the first time. Luminescence properties of Bi2ZnOB2O6:Nd3+/PMMA were analyzed on the basis on excitation and emission spectra as well as fluorescence decay profiles. Excitation spectra monitored at 1062 nm (4F3/2 → 4I11/2) indicate numerous bands related to the optical transition of Nd3+ ions: from the 4I9/2 ground state to the 4D3/2, 2P1/2, 2K15/2, 4G7/2 + 4G9/2, 2K13/2, 4G5/2 + 2G7/2, 2H11/2, 4F9/2, 4F7/2 + 4S3/2, 4F5/2 + 2H9/2, 4F3/2 excited states. Many of them may be utilized to excite near-infrared emission of Nd3+ ions. In particular, distinctive Nd3+ emissions of the 4F3/2 → 4I9/2 and 4F3/2 → 4I11/2 transitions were detected, under excitation at 514 nm. The fluorescence decay profiles monitored at 1062 nm, excited at 514 nm, show relatively long emission lifetime of the 4F3/2 → 4I11/2 transition equal to 85 μs. Raman spectroscopy was used to determine vibrational properties and homogeneity of Bi2ZnOB2O6:Nd3+/PMMA composites. The obtained results suggest that Bi2ZnOB2O6:Nd3+/PMMA composite may be applied as an effective source of near-infrared emission in a new integrated optoelectronic devices.

Poly(methyl methacrylate) organoclay composites; interactions of organic modifier with the polymer effecting thermal degradation behavior

In this work, poly(methyl methacrylate), PMMA, and its composites involving montmorillonites modified with different quaternary ammonium salts were prepared and characterized by X-ray Diffraction, XRD, Transmission Electron Microscopy, TEM, Thermogravimetry, TGA and direct pyrolysis mass spectrometry, DPMS. Increase in the interlayer spacing of the silicate layers compared to the corresponding organically modified clay was detected in X-ray diffractograms for all the PMMA composites in accordance with TEM results indicating mainly intercalated structure. The thermal stability of all PMMA composites increased compared to the neat PMMA. Thermal stability of the composites increased with the increase in the interlayer spacing of the silicate layers. This behavior was directly associated with better intercalation of PMMA chains within the galleries with larger interlayer spacing of silicate layers. Direct pyrolysis mass spectrometry results pointed out reactions between amine and hydroxyl groups of organic modifiers with the ester groups of PMMA generating methanol and thermally more stable chains.

Improved mechanical properties of PMMA composites: Dispersion, diffusion and surface adhesion of recycled carbon fiber fillers from CFRP with adsorbed particulate PMMA

In this study, composite materials were fabricated using the thermoplastic resin poly(methyl methacrylate) (PMMA) and recycled carbon fibers obtained by pulverizing carbon fiber reinforced plastics (CFRP). PMMA particles were adsorbed on the carbon fiber surfaces via electrostatic interactions, to promote the interfacial adhesion between the carbon fibers and the PMMA resin and thereby improve the dispersion of the fibers in the resin. This enhanced the mechanical properties of the composites; the yield stress and elastic modulus of the composite. As a result, the yield stress and elastic modulus of the composite improved owing to the prevention of void formation in the composite resulting from the chemical incompatibility between the filler and the resin and better dispersion of the PMMA-adsorbed carbon fibers in the resin compared to that in the unmodified fibers. This method can be applied to fabricate high-quality composites consisting of a combination of other resins and fillers.

The mechanical properties of surface treated UHMWPE fibers and TiO2 reinforced PMMA composite

Mechanical properties of hybrid PMMA composites reinforced with UHMWPE fiber and nano-titanium dioxide (2, 4, 6, and 8 wt%) was investigated. In this work, the effect of UHMWPE fiber surface treatment on tensile, flexural, and impact properties of PMMA composites was studied. The fiber loadings were varied from 0% to 20%. The addition of UHMWPE fiber had caused a decline in the tensile strength of the PMMA composite. Results revealed that the presence of titanium dioxide on the surface treated UHMWPE fiber has further enhanced the efficiency of stress transfer from the matrix to the fiber thus improved the interfacial adhesion between the UHMWPE fiber and PMMA matrix.

Mechanical properties of surface treated UHMWPE fiber and SiO2 filled PMMA composites

The hybrid reinforcement effect of surface‐treated UHMWPE fiber and SiO2 on the mechanical properties of PMMA matrix composites was investigated. When UHMWPE fiber is introduced, the tensile strength of UHMWPE fiber‐reinforced composites sharply increases. The flexural modulus was enhanced with an increase in filler loading. Flexural modulus of the treated UHMWPE/SiO2/PMMA composites was higher than that of the UHMWPE/PMMA and UHMWPE/SiO2/PMMA composites. The outcome of the better interfacial bonding between the filler and the matrix is reflected in the improvement of the mechanical properties of the treated UHMWPE/SiO2/PMMA composites. Copyright © 2017 John Wiley &amp; Sons, Ltd.

Concentration quenching of laser dyes fluorescence in variety of solid matrices and liquid solutions

Organic dye lasers are widely used in science and technology. Impregnation of dyes into polymers demonstrates many technical advantages, especially in the case when the dye monomer solution is filled inside the cavities of nanoporous glasses and then polymerized within the pores (PFNPG-P composite). This allows to create a rigid true solid-state active elements. Peculiarities of luminescence in such compositions are the subject of the work. Luminescence of 12 laser dyes was studied in liquid solutions (ethanol, MMA) and solid matrixes such as PMMA and PFNPG-P composite. Concentration dependences were measured for pyrromethenes, phenalemines, xanthenes and other types of dyes to define the quenching threshold of luminescence.